Mobile operators are beginning to use wireless networks such as wireless local area networks based on the IEEE standard 802.11 or Wi-Fi networks to offload traffic from radio access networks (RAN) or mobile networks such as, for example, Global System for Mobile Communications (GSM), cdma2000, Wideband Code Division Multiple Access (WCDMA) and Long Term Evolution (LTE)/LTE Advanced (e.g. 2G/3G/4G and beyond). Most of the current Wi-Fi deployments are totally separate from mobile networks, and are regarded as non-integrated. The usage of Wi-Fi is mainly driven due to the availability of free and wide unlicensed spectrum and the increased availability of Wi-Fi technologies in wireless terminals (WT).
Today's Indoor Wireless Systems service offerings can be categorized into anyone of a number of solutions.
A Distributed Antenna System (DAS) is a shared infrastructure model for expanding a wireless network footprint. It supports both 3GPP and Wi-Fi expansion with no interworking between both standards. Wi-Fi 802.11, is based on Unlicensed Spectrum with no seamless interworking with 3GPP. A Pico-Cell is based on 3GPP Licensed Spectrum with no seamless interworking with Wi-Fi. A Femto-Cell is based on both Licensed and Unlicensed Spectrum with no seamless interworking with either 3PGG or Wi-Fi and a Micro-Cell is based on 3GPP Licensed Spectrum with no seamless interworking with Wi-Fi.
There are various types of Wi-Fi integration to mobile networks, for simplicity, the notation of 3rd Generation Partnership Project (3GPP) networks using System Architecture Evolution (SAE)/LTE nodes are described herein by way of example only. However, it is to be appreciated that similar or like network entities or nodes may be used in any other mobile network, for example, 2G/3G/4G and beyond mobile networks such as GSM, WCDMA, Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Enhanced-UTRAN, LTE, and LTE-Advanced.
Wi-Fi integration towards the mobile core network (also known as cellular core network) is emerging as a good way to improve the end user experience further between the cellular and Wi-Fi accesses of each operator. These solutions consist mainly of the components: common authentication between 3GPP and Wi-Fi, and integration of Wi-Fi user plane traffic to the mobile core network. The common authentication is based on automatic SIM-based authentication in both access types. The Wi-Fi user plane integration provides the mobile operator the opportunity to provide the same services, like parental control and subscription based payment methods, for the end users when connected both via 3GPP and via Wi-Fi. Different solutions are specified in standardized in 3GPP Technical Specification 23.402, and may include overlay solutions (S2b, S2c) and integrated solutions (S2a), which are currently being further developed (S2a, S2b, S2c indicating the 3GPP interface/reference point name towards the packet data network (PDN) Gateway (PDN-GW)).
Wi-Fi services, even when integrated with a 3GPP network, are not set-up to provide a secondary source of data services to a wireless terminal in the event the 3GPP network services are interrupted. For a Wireless Terminal (WT), a 3GPP service interruption will require the establishment of a new data session either with another 3GPP radio node or a Wi-Fi access point. However, such an attempt on the part of the WT will not be possible if the 3GPP network is severely interrupted and no open Wi-Fi AP (AP) is in the serving area. In either of these cases, a WT cannot get continuous data service or even access a new service session. Unfortunately, such events do not provide customers of existing 3GPP operators a good user experience.
Therefore, there is a significant need to provide a mechanism to efficiently provide continuous data sessions and mobility to WTs in the event cellular (3GPP) services are interrupted.